SQL Query

[The_Chancer]

Trying to make a simple query that will give me the highest number in the column... is it this ?

SELECT MAX(order) FROM conf_rooms WHERE hotel_id=$hotel GROUP BY hotel_id

If so - how do I get the final figure ?

Cheers,

[altexis]

yeap thats it!
a few notes though... you don't need GROUP BY... it just slows down your query
also this query if fastest when you have an index in the "order" field.

how to get it? just as other queries. example:
$result = mysql_query("SELECT MAX(order) FROM conf_rooms WHERE hotel_id=$hotel") or die(mysql_error());
list($maxvalue)=mysql_fetch_array($result);

[altexis]

well... let me correct myself on this...
if you are looking for the global maximum order (regardless of hotels) read what I wrote above

but, to see the maximum order for each individual hotel_id you do need to use GROUP BY, but with one addition on this.. you have to add the "group by" field to the select list. meaning the code changes to this:

$result = mysql_query("SELECT hotel_id, MAX(order) FROM conf_rooms WHERE hotel_id=$hotel GROUP BY hotel_id") or die(mysql_error()); 
while (list($hotelID, $maxvalue)=mysql_fetch_array($result)) {
  echo "<p>there are $maxvalue orders for hotel ID $hotelID</p>\n";
}